Polymer surfactant for electroplated diamond wire saw and preparation method thereof

Abstract

The invention discloses a polymer surfactant for an electroplated diamond wire saw and a preparation method thereof, and the method comprises the following steps: carrying out prepolymerization reaction on a solution containing a propylene monomer and a quaternary ammonium salt monomer under the action of an initiator, and then adding a polymerization inhibitor to continuously carry out polymerization inhibition reaction, thereby obtaining the polymer surfactant. The macromolecular surfactant provided by the invention has higher molecular weight and charge density, is applied to production of electroplated diamond wires, improves the capability of generating weak interaction with diamond particles, endows the diamond particles with stronger positive electricity, enhances the suspension performance, improves the probability that the diamond particles are captured by a plating layer, and improves the production efficiency of the electroplated diamond wires. Meanwhile, scouring of shearing force of fluid to diamond particles in the production process is relieved, and the wiring speed is remarkably increased.

Description

Technical Field

[0001] The invention belongs to the technical field of electroplated diamond wire production and relates to a polymer surfactant used for electroplated diamond wire and a preparation method thereof. Background Art

[0002] Electroplated diamond wire is a key tool in the machining of hard and brittle materials. Its production principle is based on nickel electroplating, where the nickel coating consolidates the diamond micropowder undergoing Brownian motion in the solution, ultimately producing the electroplated diamond wire. High-quality electroplated diamond wire requires a uniform distribution of diamond abrasive particles across the wire surface to achieve excellent cutting performance. However, because commercial diamond micropowder is pre-plated with a nickel layer, it easily accumulates and agglomerates during the sanding process, resulting in plating defects and uneven wire diameters. Furthermore, to overcome the effects of fluid shear on the consolidation of diamond micropowder, actual production must sacrifice wire speed (30-50 m / min) to maintain a certain sanding capacity, resulting in low production efficiency.

[0003] Based on this, it is necessary to innovate the production process of traditional electroplated diamond wire to promote cost reduction and efficiency improvement in the electroplated diamond industry. Summary of the Invention

[0004] In response to the shortcomings of existing electroplated diamond wire preparation technology, such as the inability to balance the routing speed and the phenomenon of plating leakage, the first object of the present invention is to provide a polymer surfactant for electroplated diamond wire. The activator, due to its high molecular weight and charge density, can be used in electroplated diamond wire to increase the routing speed to 80-100 m / min without the occurrence of plating leakage.

[0005] A second object of the present invention is to provide a method for preparing a polymer surfactant for electroplating diamond wire. The method utilizes a polymerization reaction to synthesize a polymer compound. During the synthesis process, a polymerization inhibitor is added to control the molecular weight of the polymer compound. At the same time, a large amount of quaternary ammonium salt cations are introduced into the compound to make it positively charged. This facilitates the electrophoretic movement of the positively charged diamond particles, thereby changing the traditional random sanding process to active sanding and avoiding the occurrence of plating leakage.

[0006] In order to achieve the above technical objectives, the present invention provides a method for preparing a polymer surfactant for electroplated diamond wire, wherein a solution comprising an propylene monomer and a quaternary ammonium salt monomer is subjected to a prepolymerization reaction under the action of an initiator, and then an inhibitor is added to continue the polymerization inhibition reaction to obtain the electroplated diamond wire.

[0007] Conventional surfactants typically have low molecular weights. Even after reaching the critical micelle concentration (CMC), they struggle to impart sufficient zeta potential to the dispersed phase in coarsely dispersed systems (dispersed phase particle size greater than 100 nm), hindering the electroplating of diamond particles. However, the present invention utilizes the carbon-carbon double bonds of propylene monomers and quaternary ammonium salt monomers for copolymerization, and then uses a polymerization inhibitor to rationally control the molecular weight of the polymer surfactant, making it more conducive to the production of electroplated diamond wire. The propylene monomer increases molecular chain length and imparts hydrophobic ends to the polymer, while the quaternary ammonium salt monomer imparts positive charges and hydrophilic groups to the polymer.

[0008] As a preferred embodiment, the electroplated diamond wire uses a polymer surfactant with a molecular weight of 800,000 to 2,000,000. If the molecular weight of the polymer surfactant is too low, the surfactant cannot capture the diamond particles. If the molecular weight is too high, the hydrophobic end of the surfactant can trap and sweep the diamond particles, causing them to flocculate and deposit.

[0009] As a preferred embodiment, the mass ratio of the propylene monomer to the quaternary ammonium salt monomer is (1-6):(1-4). The mass ratio of the propylene monomer to the quaternary ammonium salt monomer has a direct impact on the grit density of the electroplated diamond wire. When the mass ratio is too high or too low, the grit density of the electroplated diamond wire is significantly reduced. This is because: when the mass ratio of the propylene monomer to the quaternary ammonium salt monomer is too high, the larger molecular weight of the polymer will act as a bridge, causing the diamond particles to flocculate and settle. When the mass ratio of the propylene monomer to the quaternary ammonium salt monomer is too low, the propylene monomer cannot form sufficient weak interactions with the diamond particles, reducing the electrostatic repulsion between the diamond particles and causing sedimentation. A further preferred mass ratio of the propylene monomer to the quaternary ammonium salt monomer is 1:(2-4).

[0010] As a preferred solution, the acrylic monomer includes at least one of 1-propene-3-ol, acrylic acid, 3,3-dimethylacrylic acid, methacrylic acid, methacrylamide and acrylamide.

[0011] As a preferred solution, the quaternary ammonium salt monomer includes at least one of methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride, allyltrimethylammonium chloride, and dimethyldiallylammonium chloride.

[0012] As a preferred solution, the polymerization inhibitor is diallylamine.

[0013] As a preferred solution, the initiator comprises ammonium persulfate and / or sodium bisulfite. The function of the initiator of the present invention is to initiate the polymerization of organic matter.

[0014] As a preferred embodiment, the propylene monomers are composed of 1-propene-3-ol, acrylic acid, 3,3-dimethylacrylic acid, methacrylic acid, methacrylamide, and acrylamide in a mass ratio of (0.1-0.5):(0.1-0.5):(0.5-1):(0.1-0.2):(1-2):(0.1-0.5). Monomers containing amide groups have a high reactivity ratio and tend to self-polymerize rather than copolymerize during the polymerization reaction. To ensure that the polymer contains sufficient quaternary ammonium monomers, other monomers need to be added to reduce the overall reactivity ratio of the propylene monomers.

[0015] As a preferred embodiment, the quaternary ammonium salt monomers are composed of methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride, allyltrimethylammonium chloride, and dimethyldiallylammonium chloride in a mass ratio of (0.1-0.5): (0.1-1): (0.01-0.02): (0.1-0.5). Because allyl monomers are easily inhibited during polymerization, using different monomer types can effectively increase the cationicity of the polymer, thereby ensuring that the diamond particles have a relatively positive zeta potential value.

[0016] As a preferred solution, the total concentration of the propylene monomer and the quaternary ammonium salt monomer in the solution is 100-700 g / L.

[0017] As a preferred solution, the amount of the polymerization inhibitor added is 0.1-0.2 wt.% relative to the amount of the propylene monomer added. The present invention can effectively control the reaction speed and the molecular weight of the prepared polymer by controlling the amount of the polymerization inhibitor added and the time of addition.

[0018] As a preferred solution, the prepolymerization reaction conditions are: temperature of 30-50° C., and time of 0.5-2 h.

[0019] As a preferred solution, the conditions for the inhibition reaction are: temperature of 30-50° C. and time of 5-10 min.

[0020] The advantage of the copolymerization reaction of the present invention being divided into two stages is that the propylene monomer and the quaternary ammonium salt monomer can react rapidly under the action of the initiator through the prepolymerization reaction, and after the addition of the inhibitor, the three-center four-electron structure thereof reduces the free radical activity and slows down the reaction rate, thereby effectively controlling the molecular weight of the surfactant within a shorter reaction time.

[0021] The present invention also provides a high molecular surfactant for electroplating diamond wire, which is obtained by the above preparation method.

[0022] The polymeric surfactant of the present invention achieves an optimal balance between wire speed and skip plating during the production process of electroplated diamond wire. The principle behind this approach is that the polymeric surfactant of the present invention possesses both hydrophilic and hydrophobic ends. Leveraging the self-assembly properties of amphiphilic polymer compounds in polar media, the hydrophobic ends can weakly interact with the nonpolar diamond surface, resulting in a molecular orientation with the hydrophobic ends facing inward (to the dispersed phase) and the hydrophilic ends facing outward (to the dispersion medium). The long carbon chains in the polymeric compounds provide ample sites for strong, weak interactions with the diamond particles. The diamond particles are endowed with a positive charge, which, combined with the high molecular weight of the present invention, further elevates their zeta potential, significantly enhancing their suspension properties and increasing their chances of capture by the electroplating layer. Simultaneously, the positively charged diamond particles undergo electrophoretic motion, resulting in uniform distribution across the wire. This not only inhibits particle aggregation and transforms random sanding into active sanding, reducing the possibility of skip plating, but also mitigates the impact of fluid shear forces on the diamond particles during production, thereby increasing wire speed.

[0023] As a preferred solution, the polymer surfactant is added to a nickel-containing electroplating solution for use in the sanding process of electroplating diamond wire. The polymer surfactant of the present invention has good compatibility with the nickel-containing electroplating solution and prevents nickel from stacking and agglomerating during the sanding process.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] (1) Compared with small molecule surfactants, the high molecular surfactant prepared by the present invention has a higher molecular weight and charge density. When used in the production of electroplated diamond wire, it improves the ability to have a weak interaction with diamond particles, gives the diamond particles stronger positive charge, enhances the suspension performance, and increases the probability of diamond particles being captured by the coating.

[0026] (2) The positively charged diamond particles move electrophoretically and are evenly distributed on the wire. This not only inhibits the agglomeration of particles, but also changes random sanding to active sanding, reduces the possibility of plating leakage, and alleviates the shear force of the fluid during the production process that erodes the diamond particles, significantly increasing the wire speed to 80-100 m / min.

[0027] (3) The present invention utilizes the carbon-carbon double bonds in propylene monomers and quaternary ammonium salt monomers to carry out copolymerization reaction, and then reasonably controls the molecular weight of the polymer surfactant through the polymerization inhibitor, so that it can be more conducive to the production of electroplated diamond wire.

[0028] (4) The preparation method of the present invention has a simple process and low reagent cost, which helps to reduce costs and increase efficiency in the electroplating diamond industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The infrared spectrum (a) and molecular weight distribution (b) of the polymer surfactant prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0030] The present invention is further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments. Obviously, the embodiments described below are only a part of the embodiments, and all other embodiments obtained by professionals in this field without making creative efforts are still within the scope of protection of the present invention.

[0031] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in the present invention can be purchased from the market or prepared by existing methods.

[0032] Example 1

[0033] The total concentration of the propylene monomer and the quaternary ammonium salt monomer in the aqueous solution is 300 g / L, and the mass ratio of the propylene monomer to the quaternary ammonium salt monomer is 2:1.

[0034] Among them, the propylene monomer is composed of 1-propene-3-ol, acrylic acid, 3,3-dimethylacrylic acid, methacrylic acid, methacrylamide, and acrylamide in a mass ratio of 0.1:0.1:0.5:0.1:1:0.1; the quaternary ammonium salt monomer is composed of methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride, allyltrimethylammonium chloride, and dimethyldiallylammonium chloride in a mass ratio of 0.1:0.1:0.01:0.1; the polymerization inhibitor is diallylamine; the added concentration of the initiator ammonium persulfate is 0.05 mol / L, and the added concentration of sodium bisulfite is 0.05 mol / L.

[0035] Acrylic monomer and quaternary ammonium salt monomer were added to water to form a solution, which was then transferred to a four-necked flask and heated in a 30°C waterbath with stirring for 30 minutes at a stirring rate of 500 rpm. A nitrogen purge was then introduced to remove dissolved oxygen from the water. The nitrogen purge was then stopped, and while stirring and the waterbath temperature were maintained, an initiator was added to the solution to initiate polymerization. The amount of ammonium persulfate added was 10 mL / L, and the amount of sodium bisulfite added was 10 mL / L. After 30 minutes, the waterbath was heated to 50°C, and a polymerization inhibitor was added. The reaction was continued for 5 minutes. The solution was then transferred to an ice-water bath for 10 minutes. After the ice-water bath, the solution was left at room temperature for 5 hours to produce the electroplated diamond wire using a polymer surfactant with a molecular weight of 1.58 million.

[0036] Example 2

[0037] The total concentration of the propylene monomer and the quaternary ammonium salt monomer in the aqueous solution is 300 g / L, and the mass ratio of the propylene monomer to the quaternary ammonium salt monomer is 1:2.

[0038] Among them, the propylene monomer is composed of 1-propene-3-ol, acrylic acid, 3,3-dimethylacrylic acid, methacrylic acid, methacrylamide, and acrylamide in a mass ratio of 0.1:0.1:0.5:0.1:1:0.1; the quaternary ammonium salt monomer is composed of methacryloyloxyethyltrimethylammonium chloride, acryloyloxyethyltrimethylammonium chloride, allyltrimethylammonium chloride, and dimethyldiallylammonium chloride in a mass ratio of 0.1:0.1:0.01:0.1; the polymerization inhibitor is diallylamine; the added concentration of the initiator ammonium persulfate is 0.05 mol / L, and the added concentration of sodium bisulfite is 0.05 mol / L.

[0039] Acrylic monomer and quaternary ammonium salt monomer were added to water to form a solution, which was then transferred to a four-necked flask and heated in a 30°C waterbath with stirring for 30 minutes at a stirring rate of 500 rpm. Simultaneously, nitrogen was introduced to remove dissolved oxygen from the water. Subsequently, the nitrogen purge was stopped, stirring and the waterbath temperature were maintained, and the initiator was added to the solution to initiate polymerization. The amount of ammonium persulfate added was 10 mL / L, and the amount of sodium bisulfite added was 10 mL / L. After 30 minutes, the waterbath was heated to 50°C, and a polymerization inhibitor was added. The reaction was continued for 5 minutes. The solution was then transferred to an ice-water bath for 10 minutes. After the ice-water bath, the solution was left at room temperature for 5 hours to produce the electroplated diamond wire using a polymer surfactant with a molecular weight of 1.05 million.

[0040] Example 3

[0041] The total concentration of the propylene monomer and the quaternary ammonium salt monomer in the aqueous solution is 300 g / L. The mass ratio of the propylene monomer to the quaternary ammonium salt monomer is 2:1. The propylene monomer is acrylamide; the quaternary ammonium salt monomer is dimethyldiallylammonium chloride; the polymerization inhibitor is diallylamine; the initiators ammonium persulfate and sodium bisulfite are added at a concentration of 0.05 mol / L and 0.05 mol / L, respectively. The preparation steps and conditions are the same as in Example 1, resulting in a polymer surfactant for electroplating diamond wire with a molecular weight of 1.76 million.

[0042] Example 4

[0043] The difference between this embodiment and embodiment 1 is only in the preparation parameters. The monomer types and reagent compositions are the same as those in embodiment 1. The preparation process is as follows:

[0044] Add water to the propylene monomer and quaternary ammonium salt monomer to form a solution, which was then transferred to a four-necked flask and heated in a 30°C waterbath with stirring for 30 minutes at a stirring rate of 500 rpm. Simultaneously, nitrogen was introduced to remove dissolved oxygen from the water. The nitrogen purge was then stopped, and while stirring and maintaining the waterbath temperature, the initiator was added to the solution. The amount of ammonium persulfate added was 10 mL / L, and the amount of sodium bisulfite added was 10 mL / L. After 60 minutes, the waterbath was heated to 50°C, and an inhibitor was added. The reaction was continued for 10 minutes. The solution was then transferred to an ice-water bath for 15 minutes. After the ice-water bath, the solution was left at room temperature for 5 hours to produce the electroplated diamond wire using a polymer surfactant with a molecular weight of 1.7 million.

[0045] Example 5

[0046] In this embodiment, the total concentration of the acrylic monomer and the quaternary ammonium salt monomer in the aqueous solution is 100 g / L. The mass ratio of the acrylic monomer to the quaternary ammonium salt monomer is 1:1. The remaining steps and conditions are the same to obtain an electroplated diamond wire using a polymer surfactant with a molecular weight of 900,000.

[0047] Comparative Example 1

[0048] The only difference between this comparative example and Example 1 is that the mass ratio of the propylene monomer to the quaternary ammonium salt monomer is changed to 8:1, and the remaining steps and conditions are the same to obtain a surfactant.

[0049] Comparative Example 2

[0050] The only difference between this comparative example and Example 1 is that the mass ratio of the propylene monomer to the quaternary ammonium salt monomer is changed to 1:8, and the remaining steps and conditions are the same to obtain a surfactant.

[0051] Comparative Example 3

[0052] The only difference between this comparative example and Example 1 is that no polymerization inhibitor is added, and the remaining steps and conditions are the same. The molecular weight of the obtained surfactant is 2.68 million.

[0053] Comparative Example 4

[0054] A commercially available conventional surfactant, cetyltrimethylammonium chloride, was used.

[0055] Comparative Example 5

[0056] The only difference between this comparative example and Example 1 is that no quaternary ammonium salt monomer is added, and the remaining steps and conditions are the same.

[0057] The conventional electroplating system was used to conduct experiments to obtain electroplated diamond wire data, and the sanding situation was observed using an electron microscope. The specific operation is as follows:

[0058] (1) A nickel sulfamate aqueous solution having a concentration of 40 g / L was prepared, and the pH value of the plating solution was adjusted to 4 with citric acid and sodium hydroxide to obtain an electroplating solution, and then the surfactant of the embodiment or comparative example was added separately (the concentration in the electroplating solution was 0.001 g / L).

[0059] (2) The solution obtained in step 1 was added to the sanding tank, and the diamond wire was electroplated using the pre-plating-sanding-thickening electroplating process. The wire speed was controlled at 80 m / min, the base line material was tungsten, and the wire diameter was 50 μm. The median diameter of the diamond was 5 μm; the temperature of the pre-plating process was 40 ° C, and the current density was 5 A / dm 2 , time is 5s; the temperature of the sanding process is 40℃, and the current density is 12A / dm 2 , time is 5s; the temperature of the thickening process is 40℃, and the current density is 12 A / dm 2 , time is 8s.

[0060] The electroplated diamond wires prepared in the examples and comparative examples were observed under an electron microscope, and the sand density was statistically analyzed. The results are shown in Table 1.

[0061]

[0062] Among them, the polymer surfactant prepared in Comparative Example 5 exhibited a plating leakage phenomenon during the sanding process.

Claims

1. A method for preparing an electroplated diamond wire using a polymer surfactant, characterized in that: A solution comprising propylene monomers and quaternary ammonium salt monomers is subjected to a prepolymerization reaction under the action of an initiator, and then a polymerization inhibitor is added to continue the polymerization inhibition reaction, thereby obtaining the product; The molecular weight of the polymer surfactant is 800,000 to 2,000,000; The mass ratio of the propylene monomer to the quaternary ammonium salt monomer is (1-6):(1-4).

2. The method for preparing an electroplated diamond wire using a polymer surfactant according to claim 1, wherein: The acrylic monomer includes at least one of 1-propene-3-ol, acrylic acid, 3,3-dimethylacrylic acid, methacrylic acid, methacrylamide and acrylamide; The quaternary ammonium salt monomer includes at least one of methacryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride, allyl trimethyl ammonium chloride, and dimethyl diallyl ammonium chloride; The initiator includes ammonium persulfate and / or sodium bisulfite.

3. The method for preparing an electroplated diamond wire using a polymer surfactant according to claim 2, wherein: The polymerization inhibitor is diallylamine.

4. The method for preparing an electroplated diamond wire using a polymer surfactant according to claim 2, wherein: The propylene monomers are composed of 1-propene-3-ol, acrylic acid, 3,3-dimethylacrylic acid, methacrylic acid, methacrylamide and acrylamide in a mass ratio of (0.1-0.5):(0.1-0.5):(0.5-1):(0.1-0.2):(1-2):(0.1-0.5).

5. The method for preparing an electroplated diamond wire using a polymer surfactant according to claim 2, wherein: The quaternary ammonium salt monomer is composed of methacryloyloxyethyl trimethyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride, allyl trimethyl ammonium chloride, and dimethyl diallyl ammonium chloride in a mass ratio of (0.1-0.5): (0.1-1): (0.01-0.02): (0.1-0.5).

6. The method for preparing an electroplated diamond wire using a polymer surfactant according to any one of claims 1 to 5, characterized in that: The total concentration of the propylene monomer and the quaternary ammonium salt monomer in the solution is 100-700 g / L, and the amount of the polymerization inhibitor added is 0.1-0.2 wt.% relative to the amount of the propylene monomer added.

7. The method for preparing an electroplated diamond wire using a polymer surfactant according to claim 6, wherein: The conditions of the prepolymerization reaction are: temperature of 30-50° C. and time of 0.5-2 h.

8. The method for preparing an electroplated diamond wire using a polymer surfactant according to claim 1, wherein: The conditions for the inhibition reaction are: temperature of 30-50° C. and time of 5-10 min.

9. A polymer surfactant for electroplating diamond wire, characterized by: Obtained by the preparation method according to any one of claims 1 to 8.

10. The use of a polymer surfactant in an electroplated diamond wire according to claim 9, characterized in that: The polymer surfactant is added into the nickel-containing electroplating solution and used in the sanding process of electroplating diamond wire.

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